Slashdot Mirror
Laser Fusion's Brightest Hope
First time accepted submitter szotz writes "The National Ignition Facility has one foot in national defense and another in the future of commercial energy generation. That makes understanding the basic justification for the facility, which boasts the world's most powerful laser system, more than a little tricky. This article in IEEE Spectrum looks at NIF's recent missed deadline, what scientists think it will take for the facility to live up to its middle name, and all of the controversy and uncertainty that comes from a project that aspires to jumpstart commercial fusion energy but that also does a lot of classified work. NIF's national defense work is often glossed over in the press. This article pulls in some more detail and, in some cases, some very serious criticism. Physicist Richard Garwin, one of the designers of the hydrogen bomb, doesn't mince words. When it comes to nuclear weapons, he says in the article, '[NIF] has no relevance at all to primaries. It doesn't do a good job of mimicking secondaries...it validates the codes in regions that are not relevant to nuclear weapons.'"
"That makes understanding the basic justification for the facility, which boasts the world's most powerful laser system, more than a little tricky."
NIF is a way to keep scientists at LLNL employed. That is its #1 justification, and always has been. Ask any insider.
Any hope of laser-based fusion is a pipe dream, and always has been. Nuckolls himself, the guy that started all of this, was shown a calculation in the early 1970s that proves this beyond a doubt. The problem is that the price of the target is many many times the value of the electricity it could produce.
Power on the grid right now is selling for about 3.3 cents a kWh. (see http://www.ieso.ca/imoweb/marketdata/markettoday.asp)
NIF, if it worked, which it doesn't aims to produce about 20 MJ a "shot". Under good conditions you might convert 25% of that to electrical power (don't quote gas peaker efficiencies, they're a different cycle). So we might get 5 MJ per shot.
If you're not familiar with MJ, it's a measure of energy. kWh is a more common one, so I'll convert 5 MJ = 1.39 kWh.
So at current prices, each shot might produce about 5 cents worth of power.
Now simply look at the target. It's a gold-covered cylinder machined to the sixth decimal place accuracy, capped on it's open end by double-pane windows of some incredibly clear optical system, inside of which is an equally perfectly machined plastic sphere containing the fuel that's cryogenically frozen on the inside and then smoothed using an IR laser.
The targets costs thousands and thousands of dollars per shot. And might (if it ever works) delivers a few cents of power. See the problem?
When this was first pointed out to Nuckolls in the early 1970s he worried, and then ignored it. He proposed a system with such high gain that the fuel would be delivered from a perfume mister that would self-form through surface tension into a ball that would be close enough for comfort.
We've spent 40 years learning about the physics of ICF, and what we've learned is that there is absolutely no way this could possibly work. The physics just isn't there. So instead we've pushed ahead with ever less-cost-efficient machines with ever-less-convincing excuses for doing so. Nova, built in the 1980s, was only 2-fold less successful in reaching break-even than NIF. However, NIF costs well over 10 times as much. The price efficiency is *dropping* with every generation.
AFAIK the only things successfully extracted from seawater on an industrial scale are sea salt and water.
... and fish ;)
I don't care if it's 90,000 hectares. That lake was not my doing.